Image forming apparatus, method, and medium

ABSTRACT

In a case where an image forming apparatus operates as a master station determining a communication channel used in wireless communication, the image forming apparatus transmits a second trigger frame that includes information indicating inexecution of carrier sensing and complies with an Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, to a slave station apparatus connected to the master station.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an image forming apparatus, a method,and a medium.

Description of the Related Art

Japanese Patent Application Laid-Open No. 2012-19487 discusses atechnique that enables an image forming apparatus to concurrentlyperform wireless communication in an infrastructure mode through anaccess point and wireless communication in an ad hoc mode.

In recent years, wireless communication has been used in various cases,and it is desirable to provide wireless communication with highconvenience.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, an image formingapparatus includes a communication control unit configured to enableboth a first mode in which wireless communication is performed via anexternal access point outside the image forming apparatus and a secondmode in which wireless communication is performed not via the externalaccess point outside the image forming apparatus, a reception unitconfigured to receive a first trigger frame including information aboutexecution of carrier sensing, from the external access point outside theimage forming apparatus while the first and second modes are enabled,the first trigger frame complying with an Institute of Electrical andElectronics Engineers (IEEE) 802.11 standard, a first transmission unitconfigured to transmit, in a case where the first trigger frame includesinformation indicating execution of carrier sensing, data afterexecuting carrier sensing, a second transmission unit configured totransmit, in a case where the image forming apparatus operates as amaster station determining a communication channel used in wirelesscommunication of the second mode while the first mode and the secondmode are enabled, a second trigger frame including informationindicating inexecution of carrier sensing, to a slave station apparatusconnected to the master station, the second trigger frame complying withthe IEEE802.11 standard, and a print processing unit configured toperform print processing on a sheet based on print data received fromthe slave station apparatus.

Further features of the present invention will become apparent from thefollowing description of embodiments with reference to the attacheddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an example of a systemconfiguration according to an embodiment.

FIG. 2A is a block diagram illustrating an example of a hardwareconfiguration of a mobile terminal. FIG. 2B is a block diagramillustrating an example of a hardware configuration of an image formingapparatus.

FIG. 3 is a block diagram illustrating an example of a functionalconfiguration of an access point.

FIG. 4 is a diagram illustrating an example of communication processingaccording to the present embodiment.

FIG. 5 is a diagram illustrating an example of a frame configuration.

FIG. 6 is a diagram illustrating an example of a frame configuration.

FIG. 7 is a diagram illustrating an example of a frame configuration.

FIG. 8 is a diagram illustrating an example of communication processingaccording to the present embodiment.

FIG. 9 is a flowchart performed in the image forming apparatus.

DESCRIPTION OF THE EMBODIMENTS

An embodiment of the present invention is described in detail below withreference to drawings. It should be noted that the embodiment is merelyillustrative, and specific examples of components, processing steps,display screens, and the like are not intended to limit the scope of thepresent invention unless otherwise noted.

(System Configuration)

FIG. 1 illustrates a configuration example of a system according to thepresent embodiment. As an example, the system is a wirelesscommunication system in which a plurality of communication apparatusescan wirelessly communicate with one another. In the example of FIG. 1 ,the system includes an access point 131, a multifunctional peripheral(MFP) 151, and a mobile terminal 101. The mobile terminal 101 isillustrative, and can be a laptop computer or a smartphone.

The MFP 151 includes a printing function, a reading function (scanner),and a facsimile (FAX) function. The MFP 151 according to the presentembodiment further includes a communication function that can performwireless communication with the mobile terminal 101. In the presentembodiment, a case where the MFP 151 is used is described as an example;however, an apparatus is not limited thereto. For example, in place ofthe MFP 151, a facsimile apparatus, a scanner apparatus, a projector, ora printing apparatus having a single function can be used. In thepresent embodiment, an apparatus including a printing function is alsoreferred to as an image forming apparatus in some cases.

The access point 131 is provided separately from (outside) the mobileterminal 101 and the MFP 151, and operates as a base station apparatusfor wireless local area network (WLAN). The access point 131 is alsoreferred to as an external access point 131 or an external wireless basestation (or external master station) in some cases. The MFP 151 having aWLAN communication function can perform communication in aninfrastructure mode of the WLAN through the access point 131. In thefollowing, the access point is also referred to as an “AP” in somecases. Further, the infrastructure mode is also referred to as a“wireless infrastructure mode” in some cases.

The infrastructure mode is a mode in which the MFP 151 communicates withanother apparatus through an external apparatus (e.g., access point 131)forming a network. Connection with the external access point establishedby the MFP 151 operating in the infrastructure mode is referred to asinfrastructure connection. In the present embodiment, the MFP 151operates as a slave station and the external access point operates as amaster station in the infrastructure connection. In the presentembodiment, a master station is an apparatus determining a communicationchannel used in a network to which the master station belongs, and aslave station is an apparatus that does not determine a communicationchannel used in the network to which the slave station belongs, and theslave station uses the communication channel determined by the masterstation.

The access point 131 performs wireless communication with a(authenticated) communication apparatus having permission of connectionto the access point 131, and relays wireless communication between thecommunication apparatus and another communication apparatus. Further,the access point 131 can be connected to, for example, a wiredcommunication network, and relay communication between a communicationapparatus connected to the wired communication network and anothercommunication apparatus wirelessly connected to the access point 131.

Each of the mobile terminal 101 and the MFP 151 can use their own WLANcommunication function to perform wireless communication in a wirelessinfrastructure mode via the external access point 131 or in apeer-to-peer mode not via the external access point 131. In thefollowing, the peer-to-peer mode is referred to as a “P2P mode”. Thecommunication not performed via the external access point 131 isreferred to as direct wireless communication in some cases. The P2P modeincludes a Wi-Fi Direct® mode and a software AP mode. In the following,Wi-Fi Direct® is referred to as WFD in some cases. The P2P mode iscompliant with the Institute of Electrical and Electronics Engineers(IEEE) 802.11 series.

The P2P mode is a mode in which the MFP 151 directly communicates withanother apparatus, such as the mobile terminal 101. That is, thecommunication is not performed via an external apparatus that forms anetwork. In the present embodiment, the P2P mode includes an AP mode inwhich the MFP 151 operates as an access point. Connection information(SSID and password) relating to the access point enabled in the MFP 151in the AP mode is optionally set by a user. The P2P mode can include,for example, the WFD mode for the MFP 151 to perform communicationthrough WFD. Which of a plurality of WFD-adaptive apparatuses operatesas a master station is determined based on, for example, a sequencecalled Group Owner Negotiation. Note that the master station can bedetermined without execution of Group Owner Negotiation. In particular,a WFD-adaptive apparatus functioning as the master station is referredto as a group owner. The connection with another apparatus establishedby the MFP 151 operating in the P2P mode is referred to as directconnection. In the present embodiment, in the direct connection, the MFP151 operates as the master station, and the other apparatus (e.g.,mobile terminal 101) operates as the slave station.

A configuration of the mobile terminal according to the presentembodiment, and a configuration of a communication apparatus that cancommunicate with the mobile terminal according to the present embodimentwill now be described with reference to FIGS. 2A and 2B. In the presentembodiment, the following configurations are described as an example;however, the present embodiment is applicable to an apparatus that cancommunicate with the communication apparatus, and functions are notparticularly limited to the functions illustrated in the figures.

The mobile terminal 101 includes an input interface 102, a centralprocessing unit (CPU) 103, a read only memory (ROM) 104, a random accessmemory (RAM) 105, an external storage device 106, an output interface107, a display unit 108, a keyboard 109, a communication unit 110, ashort-range wireless communication unit 111, a network interface 112,and a universal serial bus (USB) interface 113. The CPU 103, the ROM104, the RAM 105, and the like form a computer of the mobile terminal101. The input interface 102 is an interface for receiving data input oran operation instruction from the user when an operation unit such asthe keyboard 109 is operated. The operation unit can be a physicalkeyboard, physical buttons and the like, or a software keyboard,software buttons, and the like displayed on the display unit 108. Inother words, the input interface 102 can receive input (operation) fromthe user via the display unit 108.

The CPU 103 is a system control unit and controls the whole of themobile terminal 101. The ROM 104 stores fixed data, such as controlprograms to be executed by the CPU 103, a data table, and a built-inoperating system (OS) program. In the present embodiment, the controlprograms stored in the ROM 104 perform software execution control, suchas scheduling, task switching, and interruption processing, undermanagement of the built-in OS stored in the ROM 104.

The RAM 105 includes a static random access memory (SRAM) needing abackup power supply. The RAM 105 holds data by using a primary battery(not illustrated) for data backup. Therefore, the RAM 105 can storeimportant data, such as program control variables, withoutvolatilization. Further, the RAM 105 includes a memory area wheresetting information on the mobile terminal 101, management data on themobile terminal 101, and the like are stored. The RAM 105 is also usedas a main memory and a work memory for the CPU 103.

The external storage device 106 stores, for example, a print informationgeneration program generating print information interpretable by the MFP151. The output interface 107 is an interface controlling the displayunit 108 to display data or to notify a state of the mobile terminal101.

The display unit 108 includes a light-emitting diode (LED) and a liquidcrystal display (LCD) to display data and notify the state of the mobileterminal 101. The communication unit 110 is connected to an apparatus,such as the MFP 151 and the access point (AP) 131, to perform datacommunication. For example, the communication unit 110 can be connectedto an access point (not illustrated) in the MFP 151. When thecommunication unit 110 and the access point in the MFP 151 areconnected, the mobile terminal 101 and the MFP 151 can perform P2Pcommunication. The communication unit 110 can directly communicate withthe MFP 151 through wireless communication, or can communicate with theMFP 151 through the external apparatus, such as the AP 131 presentoutside the mobile terminal 101 or the MFP 151. The external apparatusincludes an external access point (e.g., AP 131) present outside themobile terminal 101 and the MFP 151, and an apparatus that can relaycommunication via other than the access point. In the presentembodiment, a wireless communication scheme used by the communicationunit 110 is Wireless Fidelity® (Wi-Fi) that is a communication standardcomplying with the IEEE802.11 series. Examples of the access point 131include a wireless LAN router.

The short-range wireless communication unit 111 is wirelessly connectedto an apparatus, such as the MFP 151, in a short-range, to perform datacommunication, and performs communication by a communication schemedifferent from the communication scheme of the communication unit 110.

The short-range wireless communication unit 111 can be connected to, forexample, a short-range wireless communication unit 157 in the MFP 151.Examples of the communication scheme include Near Field Communication(NFC), Bluetooth® Classic, Bluetooth® Low Energy (BLE), and Wi-Fi Aware.

The network interface 112 is a connection I/F controlling wirelesscommunication processing and communication processing via a wired LANcable.

The USB interface 113 is a connection I/F controlling USB connectionthrough a USB cable. More specifically, the USB interface 113 is aninterface that is connected to an apparatus, such as the MFP 151 and theexternal access point 131, via the USB to perform data communication.

The MFP 151 will now be described in relation to FIG. 2B. The MFP 151includes a ROM 152, a RAM 153, a CPU 154, a print engine 155, acommunication unit 156, the short-range wireless communication unit 157,an input interface 158, an operation unit 159, an output interface 160,a display unit 161, a network interface 162, and a USB interface 163.The ROM 152, the RAM 153, the CPU 154, and the like for a computer ofthe MFP 151.

The communication unit 156 controls communication processing using eachinterface. As a mode for communication using the communication unit 156,the MFP 151 can operate in, for example, the infrastructure mode and theP2P mode.

More specifically, the communication unit 156 can operate as the accesspoint in the MFP 151. For example, when the user instructs to enable theaccess point in the MFP 151, the MFP 151 operates as the access point.In the present embodiment, a wireless communication scheme used by thecommunication unit 156 is a communication standard complying with theIEEE802.11 series. In the following description, Wi-Fi® (Wi-Ficommunication) is a communication standard complying with the IEEE802.11series. The communication unit 156 can include hardware functioning asthe access point, or can operate as the access point by software causingthe communication unit 156 to function as the access point. In a case ofoperating as the master station, the communication unit 156 can maintainP2P wireless connection with a predetermined number or less than thepredetermined number of (e.g., three or less) slave stations inparallel. For example, the P2P wireless connection may be maintainedwith three slave stations in parallel or it may be maintained with lessthan three slave stations in parallel. The communication unit 156 canperform wireless communication using a frequency band selected from 2.4GHz, 5 GHz, and 6 GHz.

The short-range wireless communication unit 157 is wirelessly connectedto an apparatus, such as the mobile terminal 101, in a near field, andcan be connected to, for example, the short-range wireless communicationunit 111 in the mobile terminal 101. Examples of the communicationscheme include NFC, Bluetooth® Classic, BLE, and Wi-Fi Aware.

The RAM 153 includes an SRAM needing a backup power supply. The RAM 153holds data by using a primary battery (not illustrated) for data backup.The RAM 153 can thereby store important data, such as program controlvariables, without volatilization. The RAM 153 also includes a memoryarea storing setting information on the MFP 151 and management data forthe MFP 151. The RAM 153 is also used as a main memory or a work memoryfor the CPU 154. The RAM 153 stores a reception buffer for temporarilystoring the print information received from the mobile terminal 101 andvarious kinds of information.

The ROM 152 stores fixed data, such as control programs to be executedby the CPU 154, a data table, and an OS program. In the presentembodiment, the control programs stored in the ROM 152 perform softwareexecution control, such as scheduling, task switching, and interruptionprocessing, under management of the built-in OS stored in the ROM 152.

The CPU 154 is a system control unit and controls the whole of the MFP151.

The print engine 155 performs print processing forming an image on arecording medium (e.g., a sheet) by applying a recording agent (e.g.,ink) to the recording medium, based on information stored in the RAM 153and a print job received from the mobile terminal 101 or the like, andoutputs a print result. The print job transmitted from the mobileterminal 101 or the like typically has a large data amount, and thus theprint job is desirably communicated using a communication scheme thatcan perform high-speed communication. The MFP 151 therefore receives theprint job through the communication unit 156 that can perform high-speedcommunication compared with the short-range wireless communication unit157. The printing using the ink is illustrative, and the printing can beperformed by an electrophotographic method using toner. Further, the MFPcan be of a cartridge type in which an ink cartridge is mounted, or of atype in which the ink is replenished to an ink tank of the MFP from anink bottle.

A memory, such as an external hard disk drive (HDD) and a secure digital(SD) card, can be mounted as an optional device on the MFP 151, andinformation stored in the MFP 151 can be stored in the memory.

The input interface 158 is an interface receiving data input and anoperation instruction from the user when the operation unit 159 (e.g.,physical buttons) is operated. The operation unit can be a softwarekeyboard, software buttons, or the like displayed on the display unit161.

In other words, the input interface 158 can receive input from the userthrough the display unit 161.

The output interface 160 is an interface controlling the display unit161 to display data or to notify a state of the MFP 151.

The display unit 161 includes an LED or an LCD, and displays data ornotifies the state of the MFP 151.

The USB interface 163 is an interface controlling USB connection via aUSB cable. More specifically, the USB interface 163 is an interfaceconnected to an apparatus, such as the mobile terminal 101 and theexternal access point 131, via the USB to perform data communication.

FIG. 3 is a block diagram illustrating a functional configurationexample of the AP 131. The AP 131 includes, as a functionalconfiguration, a wireless LAN control unit 301, a trigger frame controlunit 302, a received-frame analysis unit 303, a UI control unit 304, astorage unit 305, and a band allocation unit 306.

The wireless LAN control unit 301 performs control to transmit/receive awireless signal to/from another wireless LAN communication apparatus.The wireless LAN control unit 301 is realized by, for example, programscontrolling a baseband circuit, a radio frequency (RF) circuit, and anantenna for wireless LAN. The wireless LAN control unit 301 performswireless LAN communication control according to the IEEE802.11 standardseries, and performs wireless communication with a station (STA)complying with the IEEE802.11 standard series.

The trigger frame control unit 302 performs control to transmit TriggerFrame to a STA that has been successfully authenticated, through thewireless LAN control unit 301. When receiving Trigger Frame, the STAtransmits an uplink (UL) frame to respond to the frame. When receivingthe UL frame through the wireless LAN communication unit 301, the AP 131interprets contents of the received UL frame using the received-frameanalysis unit 303. For example, in a case where the received UL frameincludes information on an access category (AC), the received-frameanalysis unit 303 analyzes and acquires information on the AC, andgrasps that the STA as a transmission source of the UL frame includestransmission object data on which AC.

The band allocation unit 306 determines a width and a center frequencyof a frequency band to be allocated for data transmission of each STA,and a time period to which the frequency band is allocated, based on theinformation acquired by the received-frame analysis unit 303. In otherwords, the band allocation unit 306 determines a timing and a frequencyrange of wireless resources to be allocated to each STA. The triggerframe control unit 302 notifies each STA of information on theallocation determined by the band allocation unit 306 through TriggerFrame, and causes each STA to transmit the UL frame based on theallocation.

The UI control unit 304 is realized by a program or the like controllinghardware relating to a user interface, such as a touch panel and buttonsfor receiving operation to the AP 131 by the user (not illustrated) ofthe AP 131. The UI control unit 304 can also include a function ofpresenting information about an image, sound, or the like to the user.The storage unit 305 has a storage function realized by the ROM, theRAM, and the like storing data and programs performed by the AP 131.

In IEEE802.11ax, the frequency band is allocated with a size smallerthan 20 MHz as a conventional size, which enables a large number ofterminals to use the wireless resources at the same time. Suchallocation of the wireless communication resources is performed usingOrthogonal Frequency Division Multiple Access (OFDMA).

In IEEE802.11ax, for example, a bandwidth of 20 MHz is divided into nineblocks each including 26 sub-carriers (tones) not overlapping with oneanother on the frequency axis, and the wireless resources are allocatedto the terminals in units of blocks. The block as an allocation unit isreferred to as a resource unit (RU), and a size of the RU is determinedcorresponding to the number of terminals to which the frequencybandwidth and the wireless resources are allocated. The size of the RUis represented in numbers of tones. Examples of the numbers include 26,52, 106, 242, 484, 996, and 2×996; however, among the numbers, less thanor equal to 242 are usable in the bandwidth of 20 MHz. In a case wherethe whole bandwidth of 20 MHz is allocated to one terminal, up to 242tones can be allocated. In contrast, for example, in a case where nineterminals use the bandwidth of 20 MHz at the same time, 26 tones areallocated to each of the terminals. As described above, the frequencyband is divided by 26 tones that is a minimum allocation unit, whichenables the nine terminals to perform communication at the same timeusing the bandwidth of 20 MHz. Likewise, in a case where the frequencybandwidths of 40 MHz, 80 MHz, and 160 MHz are used, up to 18, 37, and 74terminals can perform communication at the same time, respectively.

A basic flow of multiuser (MU) UL communication will now be describedwith reference to FIG. 4 . In step S401, the AP 131 causes the triggerframe control unit 302 to transmit Buffer Status Report Request (BSRRequest). FIG. 5 illustrates a configuration example of a frametransmitted at this time. In FIG. 5 , the frame includes information onfields 501 to 508. In the following, descriptions of fields not relatingto descriptions of the present embodiment are omitted. In the presentembodiment, the AP 131, the MFP 151, and the mobile terminal 101 canperform communication according to IEEE802.11ax.

Referring back to FIG. 4 , in step S402, each STA transmits BufferStatus Report (BSR). In step S402, each STA notifies the AP 131 ofpresence/absence of data to be transmitted.

Upon receiving the BSR from each STA, in step S403, the AP 131 transmitsTrigger Frame prompting transmission of UL data based on the informationin the BSR. The frame transmitted at this time also includes, forexample, the format illustrated in FIG. 5 . In FIG. 5 , a Frame Controlfield 501 is a field that holds a value indicating, for example, TriggerFrame of IEEE802.11ax. FIG. 6 illustrates a data configuration exampleof a Common Info field 505 illustrated in FIG. 5 . The Common Info field505 includes information on sub-fields 601 to 609 as illustrated in FIG.6 . A value “0” is stored in a Trigger Type sub-field 601. A valuecorresponding to a communication period common to all STA is stored inan UL Length sub-field 602, and data amount transmittable by each STA isrepresented by the value. In a case where the value of the Trigger Typesub-field 601 is “0”, User Info fields 506-1 to 506-N are added to theframe in FIG. 5 . Details of the User Info fields 506-1 to 506-N aredescribed with reference to FIG. 7 . In FIG. 7 , each of the User Infofields includes information on sub-fields 701 to 709. Each STA isspecified by an AID sub-field 701, and an RU and a tone size allocatedto the STA are specified by an index value in an RU Allocation sub-field702. The tone size is a value indicating a width of the frequency bandthat can be allocated to each STA.

The AP 131 reserves a communication channel to transmit Trigger Frame.Further, the AP 131 divides the reserved communication channel to aplurality of resource units in a frequency range, and allocates theresource units to the terminals.

Referring back to FIG. 6 , a Carrier Sense (CS) Required sub-field 604has a length of one bit. Information indicating whether execution ofcarrier sensing is necessary or not is stored in the CS Requiredsub-field 604. In a case where information indicating that execution ofcarrier sensing is necessary is included in the CS Required sub-field604, the communication apparatus having received Trigger Frame thereforeexecutes carrier sensing. In contrast, in a case where informationindicating that execution of carrier sensing is unnecessary is includedin the CS Required sub-field 604, the communication apparatus havingreceived Trigger Frame does not execute carrier sensing.

Upon receiving Trigger Frame, in step S404, each STA transmits a UL Dataframe within a range of the data amount determined by the UL Lengthsub-field 602 of Trigger Frame. At this time, in the case where theinformation indicating that execution of carrier sensing is necessary isincluded in the CS Required sub-field 604, the STA executes carriersensing and then performs the transmission in step S404. When receivingphysical layer protocol data unit (PPDU) from each STA, the AP 131transmits Multi Block Ack (Multi BA) as reception acknowledgement instep S405.

Operation of the MFP 151 will now be described with reference to FIG. 8. It is assumed that, in the MFP 151, both the infrastructure mode andthe P2P mode are enabled/set by an instruction from the user.

For example, when the user enables the infrastructure mode of the MFP151 and enables the WFD mode, both the infrastructure mode and the P2Pmode are enabled. The MFP 151 also operates as a master station (e.g.,group owner of WFD) in the P2P communication. It is assumed that the MFP151 has received Trigger Frame from the AP 131 in step S403. In the casewhere both the infrastructure mode and the P2P mode are enabled, the MFP151 can refer to a communication channel used for infrastructurecommunication, and construct a network as the master station to performP2P communication using the same communication channel. In the casewhere both the infrastructure mode and the P2P mode are enabled, the MFP151 can refer to a communication channel used for infrastructurecommunication, and construct a network as the master station to performP2P communication using a channel different from the communicationchannel used for the infrastructure communication. In other words, inFIG. 8 , in step S403, the MFP 151 receives Trigger Frame complying withthe IEEE802.11 standard, including information about execution ofcarrier sensing, from the external access point while both theinfrastructure mode and the P2P mode are enabled.

In step S801, the MFP 151 transmits Trigger Frame because the MFP 151operates as the master station. At this time, the MFP 151 divides onecommunication channel (e.g., 20 MHz) into a plurality of resource unitsby using Trigger Frame as described above in FIG. 5 , and allocates theresource units to the STAs including the mobile terminal 101. In otherwords, the RU Allocation sub-field 702 of Trigger Frame transmitted fromthe MFP 151 includes information about the allocation of the resourceunit. Further, the CS Required sub-field 604 of Trigger Frametransmitted from the MFP 151 includes the information indicating thatcarrier sensing is unnecessary. The number of slave station apparatusesto which the resource units are allocated by the MFP 151 is the maximumnumber of slave station apparatuses that can maintain the directconnection in parallel. For example, in a case where the communicationunit 156 can maintain the P2P wireless connection with up to three slavestation apparatuses in parallel, the maximum number of slave stationapparatuses to which the resource units are allocated is three. In stepS802, the mobile terminal 101 transmits data to the MFP 151. At thistime, the mobile terminal 101 transmits the data by using the resourceunit allocated by Trigger Frame. In the present embodiment, since theinformation indicating that carrier sensing is unnecessary is set, themobile terminal 101 transmits the data to the MFP 151 without executingcarrier sensing. The MFP 151 can notify the mobile terminal 101 ofremaining amounts of consumables (ink or toner) through the directconnection. As a result, an application operating in the mobile terminal101 can display the remaining amounts of the consumables. Other statesof the MFP 151 can also be communicated through the direct connection.Examples of the other states include a state of no paper in the MFP 151,a state where a cover of the MFP 151 is opened, and an error state(e.g., paper jam) in the MFP 151.

Processing performed by the MFP 151 will now be described with referenceto a flowchart as shown in FIG. 9 . The flowchart in the presentembodiment is realized when the CPU 154 reads out programs relating tothe processing of the flowchart from the ROM 152 and executes theprograms. In step S803, MFP 151 transmits Multi Block Ack (Multi BA) asreception acknowledgement.

In step S901, the CPU 154 receives Trigger Frame described above in stepS403 of FIG. 4 , from the AP 131. In step S902, the CPU 154 checkswhether execution of carrier sensing (CS) is necessary. The processingin step S902 is realized with reference to the information on the CSRequired sub-field 604 illustrated in FIG. 6 . In a case where it isdetermined in step S902 that carrier sensing is unnecessary (NO in stepS902), the processing proceeds to step S905. In step S905, the CPU 154transmits data to be transmitted to a target apparatus through the AP131 without executing carrier sensing.

In contrast, in a case where it is determined in step S902 that carriersensing is necessary (YES in step S902), the processing proceeds to stepS903. In step S903, the CPU 154 executes carrier sensing to sense energy(power) of radio waves generated in the communication channel specifiedby Trigger Frame. In step S904, it is determined whether the sensedenergy is greater than or equal to a threshold. In a case where it isdetermined that the energy of the radio waves generated in thecommunication channel is greater than or equal to the threshold (NO instep S904), the CPU 154 determines that data cannot be transmitted tothe AP 131, and the processing returns to step S903. In the case wherethe determination result is NO in step S904, processing can proceed tostep S906 omitting the processing in step S905.

In contrast, in a case where it is determined that the power generatedin the communication channel is less than the threshold (YES in stepS904), the CPU 154 determines that data can be transmitted to the AP131, and the processing proceeds to step S905. In step S905, the CPU 154transmits data to be transmitted to the target apparatus through the AP131. For example, scan data obtained when the MFP 151 reads a document,or status information on the MFP 151 is transmitted in step S905. TheCPU 154 transmits the data to be transmitted, by using the resource unitallocated to the MFP 151 by the RU Allocation sub-field 702.

In step S906, the CPU 154 determines whether the MFP 151 operates as amaster station of the direct communication. For example, in a case wherethe user instructs to the MFP 151 to enable WFD, and the MFP 151 isdetermined to operate as a group owner by negotiation processing(comparison of intent value) with a communication partner apparatus ofthe WFD, the CPU 154 determines as YES in step S906. In a case where theuser instructs the MFP 151 to enable the software AP mode, the CPU 154determines as YES in step S906.

In step S907, the CPU 154 causes the MFP 151 to operate as a masterstation of the direct communication. In step S908, the CPU 154 transmitsTrigger Frame to a slave station (e.g., mobile terminal 101) connectedto the MFP 151. At this time, the MFP 151 sets the informationindicating that carrier sensing is unnecessary, to the CS Requiredsub-field 604 illustrated in FIG. 6 , and then transmits Trigger Frameillustrated in FIG. 5 . The CPU 154 also allocates the resource unitused by the apparatus (e.g., mobile terminal 101) connected to the MFP151, by the RU Allocation sub-field 702. In this case, the mobileterminal 101 transmits data to the MFP 151 by using the allocatedresource unit. For example, the mobile terminal 101 transmits print datato the MFP 151 by using the allocated resource unit.

In FIG. 9 , a mode in which steps S906 to S908 are performed after stepsS901 to S905 is described; however, the CPU 154 may perform theprocessing in a reverse order. In other words, after steps S906 to S908are performed, steps S901 to S905 can be performed. Further, steps S901to S905 and steps S906 to S908 can also be performed in parallel.

In a case where the infrastructure communication is disabled and thedirect communication is enabled, the CPU 154 can perform steps S906 toS908.

According to the present embodiment, even in the case where execution ofcarrier sensing is instructed from the AP 131, the MFP 151 instructs theslave station connected to the MFP 151 to transmit data withoutexecuting carrier sensing. As a result, the slave stations including themobile terminal 101 can efficiently transmit print data and the like,and for example, the user can reduce a time after instruction ofprinting until acquisition of a printed product.

The present invention can be realized by supplying a program realizingone or more functions of the above-described embodiment to a system oran apparatus through a network or a storage medium, and causing one ormore processors in a computer of the system or the apparatus to read outand execute the program. Further, the present invention can be realizedby a circuit (e.g., application specific integrated circuits (ASIC))realizing one or more functions.

According to the present embodiment, it is possible to provide a moreefficient wireless communication technique.

OTHER EMBODIMENTS

Embodiment(s) of the present invention can also be realized by acomputer of a system or apparatus that reads out and executes computerexecutable instructions (e.g., one or more programs) recorded on astorage medium (which may also be referred to more fully as a‘non-transitory computer-readable storage medium’) to perform thefunctions of one or more of the above-described embodiment(s) and/orthat includes one or more circuits (e.g., application specificintegrated circuit (ASIC)) for performing the functions of one or moreof the above-described embodiment(s), and by a method performed by thecomputer of the system or apparatus by, for example, reading out andexecuting the computer executable instructions from the storage mediumto perform the functions of one or more of the above-describedembodiment(s) and/or controlling the one or more circuits to perform thefunctions of one or more of the above-described embodiment(s). Thecomputer may comprise one or more processors (e.g., central processingunit (CPU), micro processing unit (MPU)) and may include a network ofseparate computers or separate processors to read out and execute thecomputer executable instructions. The computer executable instructionsmay be provided to the computer, for example, from a network or thestorage medium. The storage medium may include, for example, one or moreof a hard disk, a random-access memory (RAM), a read only memory (ROM),a storage of distributed computing systems, an optical disk (such as acompact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™),a flash memory device, a memory card, and the like.

While the present invention has been described with reference toembodiments, it is to be understood that the invention is not limited tothe disclosed embodiments. The scope of the following claims is to beaccorded the broadest interpretation so as to encompass all suchmodifications and equivalent structures and functions.

This application claims the benefit of Japanese Patent Application No.2022-031121, filed Mar. 1, 2022, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. An image forming apparatus, comprising: acommunication control unit configured to enable both a first mode inwhich wireless communication is performed via an external access point,wherein the external access point is located outside the image formingapparatus and a second mode in which wireless communication is notperformed via the external access point; a reception unit configured toreceive a first trigger frame including information about execution ofcarrier sensing, from the external access point while the first andsecond modes are enabled, the first trigger frame complying with anInstitute of Electrical and Electronics Engineers (IEEE) 802.11standard; a first transmission unit configured to transmit, in a casewhere the first trigger frame includes information indicating executionof carrier sensing, data after executing carrier sensing; a secondtransmission unit configured to transmit, in a case where the imageforming apparatus operates as a master station configured to determine acommunication channel used in wireless communication of the second modewhile the first mode and the second mode are enabled, a second triggerframe including information indicating inexecution of carrier sensing,to a slave station apparatus connected to the master station, the secondtrigger frame complying with the IEEE802.11 standard; and a printprocessing unit configured to perform print processing on a sheet basedon print data received from the slave station apparatus.
 2. The imageforming apparatus according to claim 1, further comprising a readingunit configured to read a document to acquire scan data, wherein, in acase where the carrier sensing is executed and it is determined thatsensed energy is less than a threshold, the first transmission unittransmits the scan data by using at least one resource unit allocated tothe image forming apparatus by the first trigger frame.
 3. The imageforming apparatus according to claim 1, wherein the second trigger frameincludes the information indicating inexecution of the carrier sensing,and information about allocation of at least one resource unit.
 4. Theimage forming apparatus according to claim 1, wherein a maximum numberof apparatuses to which resource units designated by the second triggerframe are allocated is equal to a maximum number of slave stationapparatuses maintainable in the wireless communication of the secondmode in parallel.
 5. The image forming apparatus according to claim 1,wherein the image forming apparatus operating as the master stationmaintains wireless connection of the second mode with a predeterminednumber or less than the predetermined number of slave stationapparatuses in parallel.
 6. The image forming apparatus according toclaim 1, wherein wireless communication of the first mode and wirelesscommunication of the second mode are performed through the samecommunication channel.
 7. The image forming apparatus according to claim1, wherein wireless communication of the first mode and wirelesscommunication of the second mode are performed through differentcommunication channels.
 8. The image forming apparatus according toclaim 1, wherein the image forming apparatus performs wirelesscommunication using a frequency band selected from 2.4 GHz, 5 GHz, and 6GHz.
 9. A method for performing a print job by an image formingapparatus (151), the method comprising: setting a first mode in whichwireless communication is performed via an external access point,wherein the external access point is located outside the image formingapparatus and a second mode in which wireless communication is notperformed via the external access point; receiving a first trigger frameincluding information about execution of carrier sensing, from theexternal access point while the first and second modes are enabled, thefirst trigger frame complying with an Institute of Electrical andElectronics Engineers (IEEE) 802.11 standard; transmitting via a firsttransmission means, in a case where the first trigger frame includesinformation indicating execution of carrier sensing, data afterexecuting carrier sensing; transmitting via a second transmission means,in a case where the image forming apparatus operates as a master stationconfigured to determine a communication channel used in wirelesscommunication of the second mode while the first mode and the secondmode are enabled, a second trigger frame including informationindicating inexecution of carrier sensing to a slave station apparatusconnected to the master station, the second trigger frame complying withthe IEEE802.11 standard; and performing print processing on a sheetbased on print data received from the slave station apparatus.
 10. Acomputer-readable medium having stored thereon a computer programcomprising instructions, which when executed by an image formingapparatus causes the image forming apparatus to perform the method ofclaim 9.